60 BuUetin Wisconsin Natural History Society. [Vol. 6, Nos. 1 — 2. 
perate, partly boreal) — Transition, and arctic — Boreal. In Wis- 
consin latitude is of greater moment and altitude of only second- 
ary importance, since the contour of the state is with few excep- 
tions comparatively flat. 
Due to the fact that dragon-flies are little influenced by consi- 
derations of food since they are omnivorous, their distribution ex- 
ceeds that of the species of most orders of insects. Wherever there 
is water the dragon-flies of that respective life area are likely to 
occur. A very interesting illustration of the similarity of the Odo- 
nata throughout a life zone is the striking resemblance of the 
fauna of the White Mountains of New Hampshire and of North- 
ern Wisconsin. The White Mountains are placed in the miidst of 
a trans-austral region, and because of their altitude the character 
of their fauna and flora is boreal. Whatever records of insects we 
have from boreal Wisconsin are identical with the White Moun- 
tains records. 
SEASONAL DISTRIBUTION. Imagos fly from April to 
November. But the great months for dragon-flies are June and 
July. Some species fly during the greater part of the season, 
while others are seen for but a very short time. The twilight hours 
of evening are the favorite hours of hunting and also of trans- 
formation. Species, however, chiefly of the Libellulinse and Agri- 
oninas, fly also in the morning, but at the time their flight is stiff 
and slow, owing to the chill of the night. 
It is doubtful whether the Odonata normally hibernate ; but a 
specimen of Anax junius has come under my observation which 
was still alive in March when it was blown down from beneath the 
eaves of a building where it had passed the winter. Such cases 
are however very unusual. 
FOOD HABITS AND ECONOMIC VALUE. Throughout 
all stages of its life the dragon-fly is carnivorous, and will eat 
anything that it is able to capture and hold. The creature is in- 
satiate and with its predatory instinct it preys all the time, even 
